1. Field of the Invention
The present invention relates to a press apparatus configured to press a workpiece placed between a pair of heating plates. Specifically, the present invention relates to a press apparatus configured to execute both hot pressing and cold pressing for a single workpiece.
2. Related Art
Conventionally, a laminate molded product is produced by pressing a workpiece made of material such as resin material and copper foil (hereinafter referred to as a “product,” which includes a molded product after the pressing) between a pair of heating plates with high temperature (hot pressing), and then, by pressing the product between a pair of cooling plates with low temperature (cold pressing). For example, Japanese Patent Provisional Publication No. 2003-205399 (hereinafter referred to as '399 Publication) discloses a press apparatus configured to control the temperature of plates within a range of a room temperature to a temperature for molding (e.g. several hundred degrees C.), so that the plates can serve as both the heating plate and cooling plate.
The press apparatus disclosed in the '399 Publication has an advantage that the size of the entire apparatus could be reduced, since the hot pressing and the cold pressing are executed in a single press apparatus. However, since the temperature of the plates of the press apparatus disclosed in '399 Publication is varied between the room temperature and the several hundred degrees C., it takes time to change the temperature of the plates to an intended temperature when a plurality of products are pressed successively, and it causes inefficiency of manufacturing the products.
Additionally, Japanese Patent Provisional Publication No. SHO 61-76301 (hereinafter referred to as '301 Publication) discloses a tandem press system that is provided with a hot pressing apparatus, a cold pressing apparatus and a carrying means for carrying a product between the hot pressing apparatus and the cold pressing apparatus. In the tandem press system disclosed in '301 Publication, since the hot pressing and the cold pressing are performed with different respective pressing apparatuses, the heating plates of the hot pressing apparatus and the cooling plates of the cold pressing apparatus have only to be maintained at a molding temperature and room temperature, respectively. Therefore, in the above tandem press system, the temperature of each of the heating plates and cooling plates is not significantly varied even when a plurality of products are pressed in series. However, unfortunately, the tandem press system, which uses two separate pressing apparatuses, has a large size of the entire system.